Note: The original doc that comes with the 748 has the dB rating as 91, this is wrong. This addendum has the corrected dB rating above of 119 dB. UL Listed UL 985 Household Fire Warning System Units (Indoor use only) For UL installations, the product is suitable for outdoor use, only for the following applications: UL464 Audible Signal Appliance UL1023 Household Burglar Alarm System Units